Best Feeding Schedule for Autoflowering Plants
All autoflowering cannabis plants , like any other plant, need nutrients to stay alive and grow. Plant nutrients are divided into Macro and Micro. Macronutrients are nutrients plants use in large quantities: Nitrogen (N), Phosphorus (P), and Potassium (K). Micronutrients are the secondary elements and are absorbed in much smaller amounts: Magnesium (Mg), Calcium (Ca), Sulfur (Su), Copper (Cu), Zinc (Zn), Iron (Fe), Manganese (Mn) among others.
Both macro and micronutrients are delivered by watering with mixed nutrients, pre-amended soil, or slow-release powder, when feeding, remember that you can always add more but never take away nutrients.
It’s easy to over or underfeed and damage your plant, that’s why we recommend following the best nutrient schedule for autoflowers, specially designed for autos.
- Week 1 Seedling – Plain water;
- Week 2 Vegetating – ⅛ veg. nutes;
- Week 3 Vegetating – ¼ veg. nutes;
- Week 4 Pre-flowering – ½ veg. nutes;
- Week 5 First signs of flowers – ¼ bloom + ⅛ veg. nutes;
- Week 6 Flowering – ½ bloom nutes;
- Week 7 Flowering – ½ bloom nutes;
- Week 8 Flowering & ripening – Flush;
- Week 9 Ripening & harvest – Flush;
1. Different Types of Nutrients
Nutrients can come in different forms. The most common are diluted in water, mixed with soil, and in powder form to be used as a slow-release top dressing or to be mixed with the medium. Usually, beginner growers ask What are the best nutrients? That will depend on your preference and method of growing, there are basically two types: organic and inorganic nutrients and there’s a big difference between them, both of them can come in the three different forms we talked above but work in completely different ways.
Organic vs Inorganic
Organic focuses on creating and maintaining a rich medium filled with microorganisms. By using organic nutrients you’re not feeding the plant directly, you are enriching the medium where microorganisms present to feed on the nutrients, breaking them down and making it easy for the plant to absorb.
Because you’re not feeding the plant directly, she can decide when and which nutrients to absorb so unless you do it on purpose, it’s really hard to have problems related to an excess or lack of nutrients.
Inorganic nutrients work by delivering an exact amount of nutrients to the roots. To be able to do this without any damage to your plant you must really know the necessities of your autoflower. The nutrients needed for optimal growth vary from strain to strain so it’s really hard to know exactly what and when to feed. Usually, you start experimenting and if you see signs of underdevelopment or deficiencies you feed a little bit more.
On top of that, you will have to adjust the amount given to an autoflower to avoid wasting nutrients (organic) and to avoid burning your plants (inorganic). Manufacturers usually make available instructions with an approximate schedule and amounts for the products they sell but they usually are directed to photoperiodic plants. Having that in mind, we recommend always starting with half the recommended amount with autoflowers.
Slow-release nutrients can come in pellets or in powder form. Usually used as a top dressing or pre-mixed with soil, this is the simplest way of feeding because it slowly releases nutrients when watering. So you don’t have to worry about feeding your plant until harvest unless you see any signs of deficiency.
The best way to water when using slow-release feeding is water more often with less water, this way the pellets or powder will dissolve faster and you won’t have any problems.
This way of feeding also comes with instructions directed for photoperiodic plants so with autoflowers you should (generally) use half of the recommended amount.
Tip: This way of feeding takes a couple of days to dissolve the pellets or powder if you water every couple of days. If you see signs of deficiency or you notice your autoflower is hungry, you can use a small amount of water-soluble nutrients to fix this immediately and give the slow-release nutrients a bit more time to dissolve.
Bottled nutrients are what everybody knows, grower, or not. These fertilizers come in liquid form and are usually synthetic, and relatively cheap due to the wide selection available.
Synthetic nutrients are popular amongst all types of growers, even though they’re not s safe as organic nutrients, you can effectively grow and harvest your plants without major problems.
You can find a lot of different brands and their quality may differ but all fertilizers will contain basically the same elements and ratio for the vegetative (3-1-2) and the blooming stage (1-2-3), so it’s just a matter of preference.
Have in mind that unlike organic feeding which focuses in creating an ecosystem in the soil, synthetic nutrients feed the roots directly so you can easily burn your autos, you should always start with a smaller dose and increase it gradually, this way you can check the signs your plant gives you and can adjust the amount of nutrients to your plant’s needs, avoid wasting nutrients and most importantly, avoid burning your plants.
Remember that because these nutrients are synthetic they’ll most likely kill the microorganisms present in the soil so (depending on the medium) you’ll have to provide all the micronutrients too, like Calcium and Magnesium, for example.
We recommend using organic nutrients when possible, this way you’ll be maintaining an ecosystem similar to what you find in nature, resulting in better tasting flowers and avoid overfeeding your autos.
2. Nutrients for the Seedling Stage
The seedling sprouts with two little leaves called Cotyledons. These leaves provide what the plant needs to survive until the first set of true leaves appear. The first two weeks of cannabis growth are the most crucial because the little seedling is establishing its root system and it is very fragile.
When to start feeding?
If you’re feeding in the seedling stage you must be very careful not to overfeed. You can start your autoflower with 1/8 of the recommended nutrients or better yet, just give the plant water for that first couple of weeks. If you overfeed your plant at this stage of growth it is highly possible that the baby plant won’t survive or if it manages to survive then the overall yield of the damaged autoflower will be greatly diminished.
Tip: Water-soluble feeding gives the plant access to the nutrients immediately.
If you are using mediums with added nutrients then you don’t need to feed the plant for the first 2-3 weeks (until the pre-flowering stage). So you can relax and forget about those nutrients at this stage of its growth.
Tip: Always read the recommendations as amended mediums contain different amounts of nutrients. Some may have the amount needed for the first weeks but others can have the amount needed up to the pre-flowering stage.
3. Nutrients for the Vegetative Stage
Photoperiodic cannabis plants have a vegetative growth stage but autoflower plants go from the seedling phase straight to flowering without the need to change the light cycle .
Some growers believe that the time when the little seedling gets its true set of leaves until it starts flowering is the vegetative growth stage for autoflowers. But it really doesn’t matter how we call this stage because we need to feed it just like a regular photo-sensitive plant in its vegetative stage.
When we see that our autoflower plant starts to grow fast we need to start giving it more nutrients. Usually, it is best to give half of the recommended dose of nutrients, but if the plant gets really bushy you can give it a full dose.
At the vegetative stage, cannabis needs a lot of Nitrogen (N) and a decent amount of phosphorus (P) and potassium (K).
No matter what the percentage of the other nutrients is, just make sure that Nitrogen (N) is available more than those other two elements. Autoflower cannabis also needs those secondary nutrients but commercial fertilizers usually have a mix of the other nutrients your plant needs in the solution.
4. Nutrients for the Pre-Flowering and Flowering Stage
After a couple of weeks in the vegetative stage, your auto will be mature enough to start developing flowers, when this happens your plants will start to develop pistils, which are a sign that your plant is entering the pre-flowering stage.
When to switch to bloom nutes?
When the first pre-flowers start to appear you need to change your feeding to a mix of half vegetative and half blooming nutrients. You need to slowly start introducing more Phosphorus (P) and Potassium (K).
Phosphorus is essential for bud production and has to be available when your autoflower enters the flowering stage. Once your autoflower starts really producing bud you should start feeding only blooming nutrients.
Some growers think that you must strictly go by the schedule when you are feeding your plants and if you don’t change your fertilizer your plant will not grow properly.
But the truth is that almost any fertilizer will do just fine. You can be very precise and if you have a lot of experience you can boost your yield with appropriate fertilizers but for beginners and medium level autoflower growers it is not as crucial. It is always best to give your plants less food than overfeed them.
5. Autoflower Nutrient Schedule
Cannabis plants don’t like to be overfed and they can easily get burned because of that, the amount needed for an autoflower depends on the strain and growing environment. The following schedule should be adjusted depending on when your plant starts flowering.
Chart for inert mediums
|2||Vegetative stage||⅛ vegetative nutrients|
|3||Vegetative stage||¼ vegetative nutrients|
|4||Pre-flowering stage||½ Vegetative nutrients|
|5||First signs of flowers||¼ bloom + ⅛ vegetative nutrients|
|6||Flowering stage||½ bloom nutrients|
|7||Flowering stage||½ bloom nutrients|
|8||Flowering & ripening||Flush|
|9||Ripening & harvest||Flush|
Have in mind that more nutrients does not result in more growth, some plants are more sensitive to nutrients. Overfeeding your autoflowers can affect your harvest because they will need time to recover and when this happens (especially in the flowering stage), it can take up to 7 days for them to recover and continue growing normally.
Note: This schedule is based on amounts recommended for photoperiodic plants, that’s why we use ½, ¼, and ⅛ amounts. If you were to use a medium with pre-added nutrients, then you should only water until you see signs of pre-flowering (around week 4) and only then start feeding following this schedule starting from the Pre-flowering stage.
6. Nutrient overfeeding
Overfeeding is the result of a too strong solution, as said above, more nutrients don’t always result in more growth and some plants are more sensitive than others.
When you don’t measure the dose of nutrients that go in your solution, you can overfeed your plants and they will surely show signs of deficiencies. Even though it’s a common problem amongst growers, the problems that come along are really serious and can end up killing your plants.
Signs of overfeeding are yellowing or yellow spots on the leaves and can be more serious if you don’t fix it, if you continue to feed a strong solution the leaves will start to brown, get crispy and die, this results in a stressed plant which will grow slower, can end up producing lower yields and ultimately die, so if you see signs of deficiencies you should flush right away, give your plant a couple of days to recover and start feeding again with a lower dose.
Have in mind that you can easily avoid this by using our feeding schedule above or just by simply using a lower dose than recommended and increase it gradually.
7. Nutrient underfeeding
Underfeeding can also hurt your plants, if you fail to provide the nutrients your autos need to produce sugars they won’t be able to grow and will show signs similar to the symptoms of overfeeding. Even though some plants can grow well without nutrients, it’s recommended you provide at least a minimum amount to make sure your harvest meets your expectations.
Remember that nutrients are extremely important so even though you may be afraid of overfeeding your plants, there’s no need to be, it’s normal for beginner growers to burn plants, even more experienced growers can burn plants when they’re trying a new nutrient brand so don’t worry.
Just make sure you learn with your mistakes and try to adjust the dose until you reach the optimal amount.
8. Flushing and when to stop feeding
Flushing consists of washing the excess nutrients from the roots and medium 1-3 weeks before harvesting. As you may know, all cannabis plants absorb nutrients to grow, when a plant absorbs nutrients there can be a nutrient build-up, although this is more common with synthetic nutrients, it can also happen with organic nutes.
Failing to flush properly can easily affect your buds, usually, plants which have not been flushed have a less potent smell and are harsher to the throat so if you want the flavor and smell of your buds to stand out, and a smoother smoke, we recommend flushing with plain water or flushing products which can be found in grow shops.
9. In Conclusion
Not only autoflowers but all plants are different in one way or another. You can follow schedules like the one we provided above but the optimal way to feed your plants is by understanding the environment you’re growing in and the cultivar you’re growing.
Our Purple Lemonade, for example, is a sturdy grower and will do perfectly fine without nutrients.
Usually, nutrients come with instructions for photoperiodic plants, learn how to adjust it with the best auto feeding schedule.